Buggy code:
public class BlueprintExtender implements BundleActivator , SynchronousBundleListener { private static final Logger LOGGER = LoggerFactory . getLogger ( BlueprintExtender . class ) ; private BundleContext context ; private ScheduledExecutorService executors ; private Map < Bundle , BlueprintContainerImpl > containers ; private BlueprintEventDispatcher eventDispatcher ; private NamespaceHandlerRegistry handlers ; private BundleTracker bt ; private ServiceRegistration parserServiceReg ; public void start ( BundleContext context ) { BlueprintExtender . LOGGER . debug ( "Starting<seq2seq4repair_space>blueprint<seq2seq4repair_space>extender..." ) ; this . context = context ; handlers = new NamespaceHandlerRegistryImpl ( context ) ; <START_BUG> executors = Executors . newScheduledThreadPool ( 3 ) ; <END_BUG> eventDispatcher = new BlueprintEventDispatcher ( context , executors ) ; containers = new HashMap < Bundle , BlueprintContainerImpl > ( ) ; ServiceReference sr = this . context . getServiceReference ( "org.osgi.service.framework.CompositeBundleFactory" ) ; if ( sr == null ) { bt = new BundleTracker ( context , ( ( ( Bundle . STARTING ) | ( Bundle . ACTIVE ) ) | ( Bundle . STOPPING ) ) , new BlueprintExtender . BlueprintBundleTrackerCustomizer ( ) ) ; } else { bt = new BundleTracker ( context , ( ( ( Bundle . STARTING ) | ( Bundle . ACTIVE ) ) | ( Bundle . STOPPING ) ) , new BlueprintExtender . BlueprintMutilBundleTrackerCustomizer ( ) ) ; } bt . open ( ) ; parserServiceReg = context . registerService ( ParserService . class . getName ( ) , new ParserServiceImpl ( handlers ) , new Hashtable < Object , Object > ( ) ) ; BlueprintExtender . LOGGER . debug ( "Blueprint<seq2seq4repair_space>extender<seq2seq4repair_space>started" ) ; } private void checkInitialBundle ( Bundle b ) { } public void stop ( BundleContext context ) { } private List < Bundle > getBundlesToDestroy ( ) { } private static int getServiceUsage ( ServiceReference ref ) { } public void bundleChanged ( BundleEvent event ) { } private void destroyContext ( Bundle bundle ) { } private void checkBundle ( Bundle bundle ) { } private boolean isCompatible ( Bundle bundle ) { } private boolean hasWildcards ( String path ) { } private String getFilePart ( URL url ) { } private String cachePath ( Bundle bundle , String filePath ) { } private URL getOverrideURLForCachePath ( String privatePath ) { } private URL getOverrideURL ( Bundle bundle , String path ) { } private URL getOverrideURL ( Bundle bundle , URL path , String basePath ) { } private void addEntry ( Bundle bundle , String path , List < Object > pathList ) { } private void addEntries ( Bundle bundle , String path , String filePattern , List < Object > pathList ) { } private class BlueprintBundleTrackerCustomizer implements BundleTrackerCustomizer { public BlueprintBundleTrackerCustomizer ( ) { } public Object addingBundle ( Bundle b , BundleEvent event ) { } public void modifiedBundle ( Bundle b , BundleEvent event , Object arg2 ) { } public void removedBundle ( Bundle b , BundleEvent event , Object arg2 ) { } } private class BlueprintMutilBundleTrackerCustomizer extends AriesBundleTrackerCustomizer { public BlueprintMutilBundleTrackerCustomizer ( ) { } public Object addingBundle ( Bundle b , BundleEvent event ) { } public void modifiedBundle ( Bundle b , BundleEvent event , Object arg2 ) { } public void removedBundle ( Bundle b , BundleEvent event , Object arg2 ) { } } }

Fix:
executors = Executors . newScheduledThreadPool ( 3 , new BlueprintThreadFactory ( "Blueprint<seq2seq4repair_space>Extender" ) ) ;